Can't select database - Wordpress
For anyone who's still looking for solutions to this problem - please, check again your wp-config.php database credentials again. I had the same problem today and tried to over-complicate the matter by searching for advanced solutions, while I had a space in my DB_NAME field (was supposed to be 'wpdb' and was ' wpdb').
This space completely messed up my connection, I was even close to reinstalling the whole thing and losing all data.
If using LAMP -
Make sure that all privileges are granted for that database to the created mysql user. Under your MYSQL shell use the below
GRANT ALL PRIVILEGES ON database_name.* TO database_user@localhost IDENTIFIED BY 'user_password';Where,
database_name = your database name as per wp-config.php
database_user = your user name as per wp-config.php
userpassword = your user password as per wp-config.php